The present invention generally relates to an expandable, shrinkable and three-dimensional lighting string unit in a Christmas decorative lighting string and more particularly to the combination structure of the lamp bulb connected in series or in parallel whereby to form a decorative lighting string.
Generally, the decorative lighting string is used around a tree, window or door, or pre-arranged on a decorative sheet or a stand. Such lighting strings are only a simply decorative lighting string. Some of the conventional lighting strings are arranged on a three-dimensional body. All of them are not any variance. Further, the package of these take up a large volume so that the tanspotation and storage are not so easy. Thus, the cost will be increased so as to reduced the customer's purchasing ability.